Rifle grenade fuze and bulletstopping device



April 22, 1969 T H, FORMAN ET AL 3,439,615

RIFLE GRENADE FUZE AND BULLET-STOPPING DEVICE Filed Feb. 20, 1959 IN VEN T0125,

Thomas HFm-'rnan United States Patent O 3,439,615 RIFLE GRENADE FUZE AND BULLET- STOPPING DEVICE Thomas H. Forman, Needham, and Edward S. Prohaska, Randolph, Mass., assignors to the United States of America as represented by the Secretary of the Army Filed Feb. 20, 1959, Ser. No. 794,784 Int. Ci. F42!) 11/42 U.S. Cl. IGZ-65.2 2 Claims This invention relates to a rifle grenade fuze and bullet stopping device and more particularly a rifle grenade which is safe even if joltcd, dropped or red at with rifle ammunition and one which can be utilized with live ammunition as well as with conventional grenade launching cartridges having no projectile.

Heretofore, rifle grenades have been capable of use only with a grenade launching cartridge which has no projectile and if such ammunition was unavailable the grenade could not be used. To use such a grenade with ammunition having a projectile would result in a serious accident.

The rifle grenade of the present invention is utilizable with the conventional grenade type cartridges, but is Ialso provided with means to decelerate and stop a projectile so that it may be used with conventional ammunition. The grenade is also provided with a fuze which is in safe condition until launched. The shock of launching is active to arm the grenade while the shock of impact with the target is effective to detonate it.

An object of this invention is to provide a ritle grenade which may be used with either grenade cartridges or live ammunition.

Another object of the invention is to provide a rifle grenade with means to decelerate and stop the projectile of live ammunition used to launch same.

Yet another object of the invention is to provide a rie grenade which will be safe from detonation before launching, but will be detonated upon impact lafter launching.

A further object of the invention is to provide a rifle grenade which is armed by the force of launching.

These and other objects will become mor apparent when reference is had to the following detailed description and drawing in which:

FIGURE 1 is an axial section through the rie grenade of the invention with the parts in the position that they assume before tiring,

FIGURE 2 is a sectional view taken on the line 2-2 of FIGURE 1,

FIGURE 3 is a sectional view taken on the line 3-3 of FIGURE l,

FIGURE 4 is a broken away axial sectional view similar to FIGURE 1 showing the parts in the position which they assume after firing, but before contact with the target, and

FIGURE 5 is a view similar to FIGURE 4 showing the parts in the position they assume after the grenade has contacted the target.

With reference to FIGURE 1 of the drawing the rifle grenade comprises an outer tube or sleeve 1 carrying the tail ns 2 at the rear end and threaded as at 3 at the forward end. Threadedly connected to the forward end of the tube is the adaptor 4 which clamps the arming member 5 to the tube and carries at its forward end the grenade body 6. The arming member 5 carries a conventional precessing arming rotor 7 having the recess 8 and through passageway 9 which carries primer 10.

The rifle grenade of the present invention may be used with the conventional grenade launching type cartridge which has no projectile, but may also be used "ice with live ammunition having a projectile. In order to be usable with live ammunition means must be provided to stop the projectile after it has entered the grenade tube 1.

The tube 1 is provided with the internal shoulder 11 which seats the housing 12. This housing carries the base 13 and is hanged at its upper end to carry the deceleration tube 14. Clamped between the deceleration tube 14 and base 13 are alternate disks 15 of armor plate and shock `absorbing material 16 such as Teilen. The deceleration tube 14 is slightly smaller than the caliber of the rie with which the grenade is to be used.

The tube 1 also carries the outer housing member 17 which seats the base member 18 in its upper end and is provided intermediate its ends with an annular groove 19. Slidably carried by the outer housing 17 is the inner housing 20 having the base member 21 at one end, a retaining ange 22 at the opposite end and an internal annular groove 23 near the upper end. The inner housing is also provided intermediate its ends with apertures 24 which carry balls 25, the balls beings received in the undulations of a latching spring 26. The inner housing 20 is spring pressed downwardly by the Belleville 'springs 27 which react between the inner housing and outer housing 12.

Slidably carried by the inner housing 20 is the centrally bored inertia element 28 which is grooved near its upper end t0 carry the latching spring 26. Near its lower end, as best shown in FIGURE 3, the inertia element is provided with apertures 29 which carry balls 30 and is of reduced diameter to slidably carry the sleeve 31.

Carried within the central bore of the inertia member 28 is the tiring pin 32 which is grooved to receive the balls 30 and is biased downwardly by spring 33 which acts against the base 21 of inner housing 20.

OPERATION The grenade is shown in FIGURE 1 with the parts in their prering and unarmed position `and is adapted to be mounted on a rifle. If live ammunition is used in the riile the projectile enters the tube 1 from the finned end and then enters the tube deceleration tube 14. Since the diameter of the deceleration tube is smaller than the outside diameter of the projectile the tube is eX- panded as the projectile passes through and thus slows the projectile considerably. After passing through the deceleration tube the projectile encounters the armor plate disks 15 and shock absorbing material 16 which are effective to completely stop the projectile.

The force of impact of the projectile or the gas presure generated by a grenade type cartridge is effective to force the outer housing 17 from the position shown in FIGURE 1 down to the position shown in FIGURE 4 against the action of Belleville spring 27. When the outer housing has so moved the groove 19 therein aligns with the apertures 24 in the inner housing. This allows the inertia member 28 to force the balls 25 outwardly to unlock the inertia member and free it to move rearwardly in the inner housing 20.

The grenade has now started its Hight and the forces of acceleration cause the inertia member 28 with the tiring pin 32 and sleeve 31 to move back against the action of spring 33 to the position shown in FIGURE 4. When the inertia element reaches this position the latch spring 26 snaps into the groove 23 of the inner housing` and because of its wavy contour locks the inertia element and inner housing together. When the inertia element and tiring pin move back the ring pin is withdrawn from the recess 8 in the arming rotor 7. The arming rotor 7 then -precesses to the position shown in FIGURE 4 by any conventional means such as a spring to align the primer with the tiring pin.

FIGURE 5 shows the position of the parts after the grenade has contacted the target and is about to detonate. When the grenade hits the target the inertia of sleeve 31 overcomes the friction which holds it on inertia element and it slides forward clear of the balls 30. It will be noted that since the outer and inner housings 17 and 20 are locked together and the inner housing 20 and inertia element 28 are locked, none of these parts can move forward on impact with the target. When the sleeve 31 moves forward to clear the balls 30 the groove in the ring pin cams the balls outwardly and the spring 33 drives the tiring pin forward into the primer to detonate the grenade.

We claim:

1. A rie grenade comprising a sleeve adapted to be mounted on a rifle, a grenade body attached to said sleeve, an outer housing slidably mounted within said sleeve, a slidable inner housing mounted within said outer housing and held against forward movement with respect to said sleeve, an inertia member carried by and locked to said inner housing, a firing pin carried by and locked to said inertia member, spring means urging said firing pin forwardly, a sleeve member surrounding the forward end of said inertia member, said outer housing being slidable in said sleeve in response to firing of said rie and effective upon sliding to unlock said inner housing and inertia member, said inner housing upon release moving to a rearward locked relation with the outer housing, said inertia member, ring pin and sleeve member being rearwardly movable in said inner housing in response to acceleration of said grenade, means to lock said inertia member to said inner housing member after having moved rearwardly, said sleeve member being movable forwardly upon impact independently of said inertia member to unlock said ring pin from said inertia member and permit said spring means to project said iring pin forwardly.

2. A rifle grenade comprising in combination a sleeve adapted to be mounted upon a rifle, a grenade body mounted on said sleeve, an arming rotor movable between safe and armed positions mounted between said sleeve and said grenade body, said rotor carrying a primer charge disposed axially out of alignment and a recess in the periphery of the rotor aligned with said sleeve, a decelerator tube within said sleeve aligned to guide the bullet, alternate decelerator blocks of armor plate and Teflon attached to the decelerator tube to absorb the shock of the bullet, an outer housing slidable with said sleeve and having an annular groove therein, an inner housing slidable within said outer housing and having apertures provided with balls at the forward end and a spring at the rear to maintain a forward position, an inertia member slidable -within said inner housing, said inertia member having an annular groove containing a latch spring, an inner sleeve slidable within the inner housing independently of said inertia member and whose forward movement is limited by the inner housing and rearward movement by the inertia member, a firing pin slidable within the inertia member and the inner sleeve and having grooves to receive a second set of balls, said firing pin held by a spring in the recess of said rotor to maintain the primer charge out of axial alignment, said outer housing moved forward by discharge of rie to release the balls of the inner housing and lock the inner and outer housings permanently together, said inertia member and the firing pin moved backward by the acceleration of the grenade to lock the inertia member permanently with the inner housing, said rotor revolving said primer charge into alignment with said sleeve to arm the grenade upon release by the backward movement of the firing pin, the inner sleeve upon impact sliding forward to release the second Set of balls and free the firing pin, and said firing pin being forced by a spring into the axially aligned primer charge to detonate the grenade.

References Cited UNITED STATES PATENTS 1,549,763 8/ 1925 Greenwell 102-75 2,853,008 9/1958 Bowles IGZ-65.2 2,883,933 4/1959 King 102-78 X BENJAMIN A. BORCHELT, Primary Examiner.

J. FOX, Assistant Examiner.

U.S. C1. X.R. 102-78 

1. A RIFLE GRENADE COMPRISING A SLEEVE ADAPTED TO BE MOUNTED ON A RIFLE, A GRENADE BODY ATTACHED TO SAID SLEEVE, AN OUTER HOUSING SLIDABLY MOUNTED WITHIN SAID SLEEVE, A SLIDABLE INNER HOUSING MOUNTED WITHIN SAID HOUSING AND HELD AGAINST FORWARD MOVEMENT WITH RESPECT TO SAID SLEEVE, AN INERTIA MEMBER CARRIED BY AND LOCKED TO SAID INNER HOUSING, A FIRING PIN CARRIED BY AND LOCKED TO SAID INERTIA MEMBER, SPRING MEANS URGING SAID FIRING PIN FORWARDLY, A SLEEVE MEMBER SURROUNDING THE FORWARD END OF SAID INERTIA MEMBER, SAID OUTER HOUSING BEING SLIDABLE IN SAID SLEEVE IN RESPONSE TO FIRING OF SAID RIFLE AND EFFECTIVE UPON SLIDING TO UNLOCK SAID INNER HOUSING AND INERTIA MEMBER, SAID INNER HOUSING UPON RELEASE MOVING TO A REARWARD LOCKED RELATION WITH THE OUTER HOUSING, SAID INERTIA MEMBER, FIRING PIN AND SLEEVE MEMBER BEING REARWARDLY MOVABLE IN SAID INNER HOUSING IN RESPONSE TO ACCELERATION OF SAID GRENADE, MEANS TO LOCK SAID INERTIA MEMBER TO SAID INNER HOUSING MEMBER AFTER HAVING MOVED REARWARDLY, SAID SLEEVE MEMBER BEING MOVABLY FORWARDLY UPON IMPACT INDEPENDENTLY OF SAID INERTIA MEMBER TO UNLOCK SAID FIRING PIN FROM SAID INERTIA MEMBER AND PERMIT SAID SPRING MEANS TO PROJECT SAID FIRING PIN FORWARDLY. 